Layered film including heteroepitaxial PN junction oxide thin film

摘要

Semiconductors of different types are formed by a crystal growth technique and joined at the interface at which rapid atomic-layer-level compositional changes occur while maintaining high crystallinity of the semiconductor layers so as to form a heterogeneous PN junction. A layered film that includes a PN junction oxide thin film is formed on a single crystal substrate. The PN junction oxide thin film is constituted by an N-type semiconductor oxide thin film and a P-type semiconductor oxide thin film that are epitaxially grown to have c-axis orientation represented by (00k).

主权项

1. A layered film formed on a single crystal substrate, comprising:
a heteroepitaxial PN junction oxide thin film including an N-type semiconductor oxide thin film and a P-type semiconductor oxide thin film that are each epitaxially grown to have c-axis orientation represented by (00k); an epitaxially grown buffer layer containing a first buffer sublayer and a second buffer sublayer and serving as an underlayer for the heteroepitaxial PN junction oxide thin film; and an epitaxially grown metal thin film disposed between the heteroepitaxial PN junction oxide thin film and the buffer layer, the metal thin film containing at least one element selected from the group consisting of Pt, Ir, Pd, Ru, and Rh; wherein: the first buffer sublayer consists essentially of a ZrO2 film; the second buffer sublayer consists essentially of a Y2O3 film; and the N-type semiconductor oxide thin film is composed of a doped perovskite-type compound represented by R(Mx,Dy)O3 or (Rx,Dy)MO3 obtained by doping a perovskite-type compound represented by general formula RMO3 with a metal D other than R and M, and the amount of the metal D is adjusted to x+y=1 and 0.03≦y≦0.3 to control epitaxial growth of the P-type semiconductor oxide thin film on the N-type semiconductor oxide thin film so that the P-type semiconductor oxide thin film has c-axis orientation represented by (00k).